Thanks to a trick from David Carlisle (see Optional arguments in verbatim environments), he helped me with the following (EDITED for T1 encoding, per egreg's suggestion):
\documentclass{article}
\usepackage{verbatimbox}
\usepackage{readarray}
\renewcommand\encodingdefault{T1}
\parskip 1ex\parindent 0em
\newenvironment{venv}{\verbatim\venvinner}{\endverbatim}
\makeatletter
\newcommand\venvinner[1][]{{\nfss@catcodes\scantokens{\gdef\tmp{#1}}}\tmp}
\makeatother
\begin{document}
\normalsize
\begin{venv}[\LARGE]
this is a test of \LARGE verbatim
\end{venv}
Back to normal text outside of verbatim
\normalsize
\begin{venv}[\large]
\tiny this is a test of \large verbatim
that begins with a \ character, which
is tricky business when using optional
arguments in a verbatim environment.
\end{venv}
Back to normal text outside of verbatim
\normalsize
\begin{venv}[\rmfamily]
Here is verbatim text in \rmfamily.
\end{venv}
\begin{venv}[\slshape]
And we have verbatim in \slshape
\end{venv}
\end{document}

p.s. I would add in closing that the verbatimbox package incorporates this kind of [optional pre-conditioning] logic in order to stuff verbatim into a box. But in that case, it must display on a single page, as a box cannot be broken across pages.
\verb? – egreg May 02 '13 at 16:52\verb, but with more options. After posting the question I thought about something like inlinelistings, but it seems to much for this operation. – cacamailg May 02 '13 at 17:01\rmfamily, I presume you mean that it is specified prior to entry into the command/environment, since otherwise it would display literally, rather than being enacted? – Steven B. Segletes May 02 '13 at 17:17listingsprovides an inline command,\lstinline. It has an optional argument for all the settings you want. There's also\lstMakeShortInlinewhich defines a shortcut for\lstinlinewhere you can have preset options for the specified shortcut. – cgnieder May 02 '13 at 17:55